The present invention relates to a combined tool for precision boring and burnishing the internal surfaces of workpieces.
Tools of this type are well known in the art and for instance disclosed in the German Offenlegungsschriften Nos. OS-2346729, OS-2362788, OS-2209234 and OS-2223696.
These known tools all have a considerable common disadvantage, namely a considerable wear of their guide bars which is due to the sagging of the feed tube and the resulting clamping of the guide bars in the bore of the workpiece. The wear of the guide bars is further increased due to the fact that during the boring the center of the machine usually does not coincide with the center of the workpiece. The clamping of the guide bars leads also often to a vibration of the bore and burnishing tool and therewith to a reduction of the surface quality, as well as to a reduction of the usual life of the tool.